It is known from European Patent Application No. 90,883 that insulating moldings which contain a press-molded mixture of a finely divided component such as pyrogenically produced silicon dioxide, an opacifier and a high temperature stable fiber, can be coated with an aqueous suspension which contains, in addition to water, a mixture of bentonite and inorganic fibers. The thermoinsulating materials thus treated can additionally have one or more coatings based on organic or inorganic surface-coating systems, silicone compositions or low-melting glazes. According to European Patent Application No. 90,883, direct application of the organic or inorganic coatings onto such thermoinsulating materials without coating with the aqueous suspension is not possible.
Surprisingly, we have found that thermoinsulating moldings containing porous, inorganic thermoinsulating materials having an adherent and durable organopolysiloxane coating thereon can be obtained without pre-coating the thermoinsulating molding, with the aqueous suspension described in European Patent Application 90,883.
It is an object of the present invention to provide thermoinsulating moldings based on a porous, inorganic thermoinsulating material which are resistant to mechanical influences such as abrasion, dirt pick-up and moisture and liquids. Another object of the present invention is to provide thermoinsulating moldings based on porous, inorganic thermoinsulating material having a coating thereon which is resistant to abrasion, moisture and liquids. A further object of the present invention is to provide thermoinsulating moldings having an adherent, durable and electroinsulating coating thereon.